Indian navy divers have recovered another burnt body from a submarine that exploded in Mumbai as they battled against the odds to find 12 remaining crewmen, the navy said on Sunday.

The diesel-powered INS Sindhurakshak exploded and sank in a military dockyard early on Wednesday, dealing a setback to India’s naval ambitions just days after it unveiled its first domestically made aircraft carrier.

Eighteen crewmen were on board when the submarine went down.

“They located and brought up the body of the sixth crew member just forward of the control room despite” poor visibility “and mangled metal”, the navy said in a statement, adding that the body was discovered late Saturday.

Divers also gained access to the forward compartment, which was destroyed in the fire, by “breaking open jammed hatches”, the statement said.

The state of the bodies and conditions within the submarine have led the navy to conclude that finding any surviving personnel is unlikely.

The ship, which had been returned by its original maker Russia earlier this year after a major refit, sank after it was engulfed by a fireball that lit up the Mumbai night sky.

The first bodies were retrieved from the submarine on Friday. Samples from the bodies of all six found have been sent for forensic tests and finger printing to establish their identities, Sunday’s statement said.

Samples have also been taken from family members of the crew and forwarded to the same testing laboratory.

The navy, which has been providing emotional support to the families of the victims, said divers would continue to make “repeated entries” into the submarine in the coming days for a comprehensive assessment of the damage.

“The present state of the submarine and various options for salvage are being assessed,” it added.

The navy also suggested that some bodies might never be found because of the fierce temperatures generated in the fire, during which some of the weapons on board - cruise missiles and torpedoes - ignited.